1. Field of the Invention
The invention is directed to an electrographic printer device for printing web-shaped recording media having different web widths with a possible return of the recording medium from the fixing station to the transfer printing station for producing duplex and color printing.
2. Description of Related Art
A high economic customer benefit and a broad flexibility are increasingly expected to modern electrographic printer systems. Both the effective utilization of materials to be printed as well as the flexible design of the print information thereby play a great part.
Continuous processing (fan fold) paper electrographic printer systems that can print a web-shaped recoding medium on one side have prevailed everywhere in the marketplace wherein high device availability given great printing volume and a broad spectrum of materials to be printed on are required. These printer systems, however, have the disadvantage that it is not possible to change between single-sided and double-sided printing. For the user, this leads both to an economically unfaorable situation as well as running contrary to the contemporary demands made of raw material utilization. Many customer-associated uses that absolutely require two-sided printing (brochures, books, etc.) can thus not be satisfied, especially since electrographic high-performance printers are especially economical when they are operated without interruption insofar as possible.
For producing multi-color printing and printing of the reverse side of the page with electrographic printer devices working with continuous stock, European Patent Publication EP-B1-01 54 695 discloses that two continuous stock printers be operated following one another, whereby the paper printed in the first printer is turned over and is subsequently printed on the second side in the second printer.
The outlay for such device is substantial due to the required, second printer.
The reference, IBM Technical Disclosure Bulletin, Vol. 22, No. 6, November 1979, pp. 2465-2466, also discloses an electrophotographic printer device for printing web-shaped recording media, with which it is possible to print the recording medium on both sides. To this end, the recording medium is taken from a supply stack, is supplied to a transfer printing station and is provided with toner images on one side. After fixing of the image on the medium, the recording medium is turned over and is again supplied to the transfer printing station. After printing the reverse side of the recording medium with toner images, another fixing in the fixing station ensues.
This old reference fundamentally describes duplex printing with continuous stock recording media. The proposal, however, never led to a procedure. Further, said electrographic printer device is only suitable for both-sided printing of the recording medium. Switching between on sided and two sided printing operating modes is not provided.
The reference XEROX DISCLOSURE JOURNAL, Vol. 9, Bo. 3, May 1984, Stanford, Conn., USA, pages 201 through 203 describes methods for duplex printing with a web-shaped recording medium using differently constructed electrophotographic printer devices. In a first duplex printing method, a toner image is first applied to a front side of the recording medium and the recording medium together with the toner image is then turned over and, simultaneously with or immediately before the turn-over operation the toner image is fixed by a first fixing means attached in the region of the turn-over means. A toner image of the reverse side is subsequently applied with the assistance of the transfer printing station, this being then in turn fixed with the assistance of a further fixing means attached at the output side with reference to the printer device. In a second method for producing duplex printing, a toner image of the front side is first applied with the assistance of the transfer printing station. After this, the recording medium is turned over and the application of the toner image of the reverse side ensues. Both toner images are then simultaneously fixed via a fixing station arranged at the output side. In a third method for producing simplex printing or a narrow or double width recording medium, the application of the sole toner image ensues with a transfer printing station that is appropriately adapted in width, to the recording medium whereby the toner image is then fixed via a width-adapted fixing station at the output side.
Switching between the individual operating modes, for example duplex and simplex printing, within a single printer device with corresponding adaptation of the paper conveying means is not provided. A special fixing station structure, moreover, is proposed for every operating mode.
As already set forth at the outset, electrographic printer devices are utilized for operation with web-shaped recording media when a high printing speed in combination with high printing quality is required. Precisely when processing high print volumes such as represented, for example, by accounting documents, statements of account, fee statements and the like, however, it can be beneficial to print, for example, in two colors in order to more clearly identify specific areas of the forms. Multi-colored printing, however, normally involves substantial outlay and reduces the printing speed.
An object of the invention is to provide an electrographic printer device for printing web-shaped recording media in changing operating modes with one and the same device that is flexibly constructed and that enables an adaptation to the greater variety of user demands by the user in a simple way.
In an electrographic printer device of the species initially cited, this object is achieved by an intermediate carrier having appertaining units such as an image-generating means, a developer station, a charging station, a cleaning station for generating toner images on the intermediate carrier that comprises a usable width of at least twice the web width of a narrow recording medium; a transfer printing station that is allocated to the intermediate carrier and accepts the recording medium, and that comprises a usable width of at least twice the web width of the narrow recording medium, a single fixing station following the transfer printing station in a conveying direction of the recording medium for fixing the toner images on the recording medium, the fixing station comprising a usable width of at least twice the web width of the narrow recording medium; and a deflection means that follows the fixing station and that can be added in dependence on the operating mode for the narrow recording medium and having an allocated return channel to the transfer printing station, whereby in a first operating mode of the printer device for multiple printing of the single, narrow recording medium, the recording medium is conducted to a use area of the fixing station via the transfer printing station proceeding from a delivery region and is resupplied to the transfer printing station and a use area of the same fixing station neighboring the use area via the deflection means proceeding from the use area of the fixing station; and in a second operating mode of the printer device for single-sided printing of one or more recording media having different web width, the recording medium or media is/are conducted to the single fixing station only via the transfer printing station proceeding from a delivery region.
Advantageous embodiments of the invention are provided by a deflection means that is fashioned as a page turn-over means such that the single, narrow recording medium is supplied to the transfer printing station turned over with respect to its front and reverse sides compared to its original supplied position.
In a further development, a deflection means that is fashioned such that, in a first operating mode, the deflection means supplies the single, narrow recording medium to the transfer printing station turned with respect to its front and reverse sides compared to its original delivery attitude and such that, in a second operating mode, the deflection means supplies the single, narrow recording medium to the transfer printing station in its original delivery attitude. One or more developer stations generating separately inkable developer zones on the intermediate carrier, may be provided whereby a corresponding developer zone on the intermediate carrier is allocated to at least each position region of the narrow recording medium upon passage through the transfer printing station. A conveyor means is allocated to the transfer printing station and engages into margin perforations of the recording medium, the conveyor means being adjustably fashioned depending on the operating mode of the printer device.
In a preferred embodiment, an LED character generator extending at least over the useable width of the intermediate carrier is provided as the image-generating means.
A method for both-sided, multi-colored printing of a web-shaped recording medium with an electrographic printer device is also provided, comprising the following steps:
applying a first sequence of toner images of a first color onto the front side of the recording medium in a first pass through the transfer printing station;
fixing the first sequence of toner images in the fixing station;
front to reverse side turning of the recording medium in the deflection means and redelivering of the recording medium to the transfer printing station;
applying a second sequence of toner images in a second color on the reverse side of the recording medium; and
fixing the second sequence of toner images in the fixing station.
The method for multi-colored printing of a web-shaped recording medium with an electrographic printer device may instead include the steps of:
applying a first sequence of toner images in a first color onto the front side of the recording medium in a first pass through the transfer printing station;
fixing the first sequence of toner images in the fixing station;
redelivering the recording medium to the transfer printing station;
applying a second sequence of toner images with a second color on the front side of the recording medium; and
fixing the second sequence of toner images in the fixing station.
The electrographic printer device of the invention comprises a usable width of at least twice the web width of a narrow recording medium. A deflection means that follows the fixing station for the narrow recording medium is adjustably fashioned, namely dependent on the operating condition of the printer device. For multiple printing of a single, narrow recording medium, for example for producing single-color or multi-color duplex printing or for producing multi-colored simplex printing, the recording medium is conducted over the transfer printing station to the fixing station and from the latter via the deflection means back to the transfer printing station and to the fixing station. For single-sided printing of a recording medium having a web width that is broader than that of the narrow recording medium or for printing a plurality of narrow recording media in parallel operation, a guidance of the recording medium ensues only over the transfer printing station to the fixing station.
In order to be able to print multi-color images, the intermediate carrier comprises developer stations having separately inkable developer zones.
The printer device employs a single fixing station designed according to accommodate the maximum recording medium width. The single fixing station is employed for all recording medium widths and in all operating modes. An adaptation of the device to the different operating modes ensues by simple add-in and switching, for example of the deflection means.
A conveyor means that is allocated to the transfer printing station and that engages margin perforations of the recording medium is fashioned to be adjustable depending on the operating mode of the printer device. The conveyor means can also be fashioned for conveying recording medium that are free of conveying holes.
A simple adaptation of the conveyor means to the greatest variety of recording medium widths is thus possible.
Without increasing the apparatus-oriented outlay compared to traditional machines, the electrographic printer device of the invention enables with one and the same device the printing of broad recording media in broadside (landscape) and long (portrait) format, the printing of narrower recording media in duplex mode, i.e. with front side and reverse side printing both in a single-color in multi-colored images, multi-colored, single-sided printing and the printing of a plurality of recording media in parallel mode.
Despite the significant enhancement in function, the device dimension, the manufacturing costs as well as the operating reliability and the dependability correspond to those of known printer machines, a need for a flexibly employable, electrographic printer device that has existed for many years being thus satisfied.